Safety-valve



' W. e. BARR. SAFETY VALVE.

Patented Sept. 23; 1884.

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XVILLIAM OQBARR, OF JERSEY CITY, NEXV JERSEY.

SAFETY-VALVE.

SPECIFICATION forming part of Letters Patent No. 305,416, dated September 23, 1884.

Application filed January 31, 1884. (No model.)

T0 at whom it may concern.-

Be it known that I, WILLIAM G. BARR, a citizen of the United States, residing at J ersey City, Hudson county, New Jersey, have invented certain new and useful Improvements in Safety-Valves, of which the following is a specification, reference being had therein to the accompanying drawings.

The object of my invention is to combine, in a safety device for steamboilers and analogous structures, two valves in such a manner that under normal conditions both valves cooperate, while in case one valve becomes inoperative the other preserves an operative condition. This object I have accomplished by constructing and arranging the valves as hereinafter described, and as illustrated in the accompanying drawings, in which:

Figure 1 is a vertical section showing both valves in a closed position. Fig. 2 is a crosssection on the line a: m, Fig. 1.

Similar letters indicate similar parts.

The letters A B designate the two valves, one of which may be termed a main valve, and the other a supplemental valve, the latter co-operating with, but being capable of operating independently of, the main valve. The main valve A is composed of a hollow cylinder occupying a vertical position in a shell, 0, while the supplemental valve 13 is composed of a disk resting on the upper end of the cylinder. The shell 0 forms a chamber for the valve-cylinder A, and is provided with a seat, D, therefor, the orifice of which seat is larger than the inner diameter of the cylinder, so that the lower end or face of the cylinder is exposed interiorly of the valve-seat, as shown in Fig. 1. The upper end of the valve-cylinder A is ground to form a seat for the valvedisk B, and the latter is exposed to the action of a weight, E, (or a spring) which thus is common to both valves, the weight being arranged on the usual lever, ll, which is fulcrumed at one end in an arm, G, of the valveshell, and engages the valve-disk by means of a stem, H, entering a central socket of the disk. For the purpose of guiding the valvedisk D when it lifts off from the cylinder, as hereinafter explained, it is constructed with a spider, I, to enter the cylinder, this spider, by its radial blades,forming an extended bearing for the valve-clisl ,without obstructing the passage of steam to the disk.

The valve-shell O is made in shape of an elbow, and the valve-seat D is in its vertical limb, which constitutes the inlet of the valvechamber, the valvecylinder A passing through the top of the other or horizontal limb thereof, which constitutes the outlet of the valvechamber. The valve-seat D is composed of a ring or cylinder, which rests 011 a shoulder, J, of the shell at the lower end, and has an outwardlyprojeeting flange, K, at the upper end, resting on the shoulder formed at the junction of the two limbs of the shell, so that the seat can be easily removed for its repair communicates with the outlet of the valvechamber, and the valve-seat D is arranged at or near the lower end of the recess. In the top of the valve-shell G, where the valve-cylinder A passes through it, is arranged a bushing, N, which rests on the shell by means of an outwardly-projecting flange, O, at the up per end, and is hollowed on the inner surface intermediate of the ends, so that it bears on the cylinder only at the ends, thus forming an extended bearing for the cylinder, with very little friction.

If desirable, the valve cylinder A may be grooved longitudinally to further reduce friction.

When the device is applied to use, the weight E is set to properly load the valves A B, and when the pressure of the steam exceeds the capacity of the weight the steam acts on the lower end or face of the cylinder A, due to the relative inner diameter of the cylinder and the orifice of the valve-seat D, to lift the valvecylinder off from its seat and permit the steam to escape through the outlet of the valve-chamher, the valve-disk B sharing the motion of 5 should become inoperative, the dis]; B lifts off from its seat under the pressure of the steam, and, opening the upper end of the cylinder,

permits the steam to escape, thus insuring safety. An important feature of the valvedisk B is its arrangement exterior of the valveshell, inasmuch as it is thus entirely relieved from back-pressure.

The effect of the recess L around the valvecylinder.

It is not intended to claim herein the broad idea of two independent valves, one seated upon the other, so that one shall maintain an operative condition in ease the other becomes inoperative; but my invention consists in attaining this object by a new organization of independently-operating valves, which, under normal conditions, cooperate to open one of two independent ports in the valve-case, while in the event of one valve becoming inoperative the other will open one of said independent ports.

What I claim as my invention is- 1. The combination, in a safety-valve for steam-boilers, of the two valves A and B, arranged as described, with the casing, within which the valve Ahas a vertical wall-seat and an end seat opening into a side port below its wall-seat, the latter forming a supplemental receiving-surface for the steam-pressure within the diameter of said end seat, and a weighted'connection for said valves, whereby the valve B will open the top outlet-port of the valve A, and the latter will open the side caseport, substantially as herein set forth.

2. The combination, in asafety-valve, of the valves A and B, the valve-seat D, and the bushing '0, with the casing havinga side port and an interior wall-recess communicating therewith between the end and wall seats of the valve A, and the weighted lever, the said casing forming a guide-bearing for the interior valve, A, and the latter forming a guide for the externalvalve, B, substantially as herein set forth.

3. The combination, with the flanged tubular bushing N and the flanged tubular seat D, of the tubular valve A, packed and seated thereby to expose its lower ring end to the steam-pressure from the boiler,'the exterior valve, B, the weighted lever F, and the shell or inelosing-case O, constructed with the interior shoulder, J, and'permitting the removal of the tubular seat, the tubular valve, and the tubular bushing, substantially as described,

for the purpose specified. ,4. The combination. substantially as hereinbefore set forth, with the'hollow cylinder composingthe mainvalve and the shell formin g the valve-chamber, of the bushing hollowed intermediate of the ends to bear against the valve-cylinder only at those points.

In testimony whereof I affix my signatu re in presence of two witnesses.

WILLIAM C. BARR,

\Vitnesses:

E. F. EDWINs, ELLIOT BRIGGS. 

